West Saint John leaks caused by water source changeover, says report
Scaly buildup inside copper pipes broke down quickly when water source changed, causing leaks
A new $40 thousand report concludes scaly material that built up over decades in the water pipes of west Saint John homes was weakened by a change in the water source, which eventually caused leaks.
The report follows over 200 complaints of leaking pipes and a series of angry public meetings that concluded in an ongoing class action lawsuit.
The problems began in September, 2017 after the city switched the water source for west side customers from Spruce Lake to groundwater from wells drilled in the South Bay area.
Just months later, in January, 2018 water department staff began to hear from homeowners whose copper pipes were leaking.
Over a three to four week period, three percent of the west side's 5400 water customers reported leaks.
Hot water tanks also began to fail.
The report submitted to city council Monday shows just how baffled drinking water experts still are about the whole experience.
The report was prepared by consultant CBCL Ltd, which worked with Dalhousie University on the study.
It concludes that what happened in west Saint John would not have been among the "anticipated outcomes" of the water changeover.
The study determined that over the previous decades the water from Spruce Lake caused a scale to build on the inside of the water pipes, and that scale is all that was keeping some of those pipes together.
The development of scale inside copper pipes is common, but this type of scale seems to be specific to the corrosive, low pH/alkalinity water of Spruce Lake said Mike Chaulk of CBCL, the report's author.
That corrosion helped form the scale that eventually hardened in the pipes actually protecting them from leaks.
The scale broke down when the water source was changed exposing pipe and joints weakened by the original corrosion.
"What we're suggesting through the data here is that the material that was already [in the pipe] didn't like the new water," said Chaulk.
Event an anomaly
Saint John Water Commissioner Brent McGovern said the risk of such a problem was identified as low and the city water system now stands out as an anomaly because of it.
"The likelihood of this event occurring is really not something we've seen at any other municipalities across the country," said McGovern.
As a precautionary measure the city introduced orthophosphate treatment to the system as a corrosion inhibitor even though there is nothing in the makeup of the South Bay well water that indicates it is corrosive.
McGovern says no new leaks have been reported since June of last year.